[Purpose] Motion influences the perceived position of stationary objects in certain conditions. We found a similar phenomenon, where rotation signals in depth influence the direction of a briefly presented face image (looking off effect). When a rotating object is replaced by a face image, the face direction appears to shift in the rotation direction of the moving object. We examined whether the phenomenon is a variation of the 2D motion effect, whether it is local effect and whether it is face specific phenomenon.

[Experiment] The rotating inducer was a 3D human head and the test stimulus was a 2D cartoon face or a wired object. In a trial, the inducer rotated around the vertical axis from one side to the other. When the inducer directed to the center (facing to the observer), a test stimulus replaced it briefly. The direction of the test stimulus varied between -4° and 4° and the observer responded the direction of the test (left or right). With in the method of constant stimuli, we measured the direction of the test object that appeared to be in straight ahead.

[Results] The perceived straight direction of the test image was shifted in the direction of the inducer rotation. The effect was the larger for the face (2.0°) than for the wired object (1.2°). When an upside down face was used, the amount of the shift reduced (1.7°). Using the depth reversed wired object, we confirmed that the effect was in 3D. We also found no effect when the inducer and the test do not overlap in space. They indicate that the effect is neither specific to face nor a 2D phenomenon, although it may be stronger for face images. They suggest that the effect is related to spatial perception rather than object or face recognition.